Wireless power transfer systems provide a convenient, safe, and reliable way to charge and power electrical devices. Traditionally, the inverters or amplifiers of the wireless power transfer system are ZVS class D inverters. The ZVS class D inverters achieve a relatively stable overall power conversion efficiency of the system. Class DE inverters can further improve the power conversion efficiency of the wireless power transfer system at a certain load impedance, but the overall power conversion efficiency cannot maintain a stable value. A major challenge of class DE inverters is how to keep the power conversion efficiency at a high level when the load impedance varies.
New methods and systems that provide improved power conversion efficiency from the wireless power transfer system to the load will assist in advancing technological needs and solving technological problems in the field of wireless power transfer.